Received: from maia.hub.org (maia-3.hub.org [200.46.204.243]) by mail.postgresql.org (Postfix) with ESMTP id 7B1696324AF for ; Wed, 23 Jun 2010 09:00:35 -0300 (ADT) Received: from mail.postgresql.org ([200.46.204.86]) by maia.hub.org (mx1.hub.org [200.46.204.243]) (amavisd-maia, port 10024) with ESMTP id 40737-05 for ; Wed, 23 Jun 2010 12:00:23 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from mx01.bfk.de (mx01.bfk.de [193.227.124.2]) by mail.postgresql.org (Postfix) with ESMTP id 23519631ADA for ; Wed, 23 Jun 2010 09:00:24 -0300 (ADT) Received: from mx00.int.bfk.de ([10.119.110.2]) by mx01.bfk.de with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) id 1OROcr-0001TW-Fl; Wed, 23 Jun 2010 12:00:17 +0000 Received: by bfk.de with local id 1OROcv-0007rA-UP; Wed, 23 Jun 2010 12:00:21 +0000 To: Ivan Voras Cc: pgsql-performance@postgresql.org Subject: Re: raid10 write performance References: <4C20CB5F.2030000@2ndquadrant.com> From: Florian Weimer Date: Wed, 23 Jun 2010 12:00:21 +0000 In-Reply-To: (Ivan Voras's message of "Wed\, 23 Jun 2010 12\:06\:56 +0200") Message-ID: <82fx0et0ve.fsf@mid.bfk.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=0.79 tagged_above=-10 required=5 tests=BAYES_50=0.8, T_RP_MATCHES_RCVD=-0.01 X-Spam-Level: X-Archive-Number: 201006/392 X-Sequence-Number: 39248 * Ivan Voras: > On the other hand, RAID10 is simple enough that soft-RAID > implementations should be more than adequate - any ideas why a dedicated > card has it "slow"? Barrier support on RAID10 seems to require some smallish amount of non-volatile storage which supports a high number of write operations per second, so a software-only solution might not be available. --=20 Florian Weimer BFK edv-consulting GmbH http://www.bfk.de/ Kriegsstra=DFe 100 tel: +49-721-96201-1 D-76133 Karlsruhe fax: +49-721-96201-99